Since 1947 -- after the end of World War II and at the beginning of the Cold War -- the Science and Security Board of the ...

A team of physicists has discovered a surprisingly simple way to build nuclear clocks using tiny amounts of rare thorium. By ...

For decades, atomic clocks have provided the most stable means of timekeeping. They measure time by oscillating in step with the resonant frequency of atoms, a method so accurate that it serves as the ...

Optical lattice clocks are emerging timekeeping devices based on tens of thousands of ultracold atoms trapped in an optical lattice (i.e., a grid of laser light). By oscillating between two distinct ...